Speed-control system



C. S. BUSHNELL SPEED CONTROL $Y $TEM Filed March 16 INVEN OR ATTORNEY Patented May 11, 1926.

UNITED-STATES PATENT OFFICE.

CHARLES S. BUSHNELL, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAIL- WAY SIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OF NEW YORK.

SPEED-CONTROL SYSTEM.

Application filed March 18, 1922. Serial No. 544,265.

This invention relates to train control systems, and more particularly to an arrangement of parts and circuits for making an-automatic brake application dependent upon the time taken by a train in passing between two control points. In certain types of train control systems where it is desired to make the automatic control dependent upon mechanism is started or rendered eiiective,

as the train passes the first or initiating. control point, and automatically returns to its initial or normal condition after the lapse of'a predetermined time-interval, vObviously, it is essential that such timing mechanism be accurate, eflicient, and reliable in its performance; and one of the principal objects of this invention is to devise an organization of parts and circuits by means of which the desired intervals of time may be automatically measured, and with which any failure of an. essential part will been the side of safety. 1

Various other specific objects, advantages, and characteristic features of the invention will appear hereinafter, as the description progresses.

In the accompanying drawings, Figure lv illustrates in a conventional and diagrammatic manner the trackway equipment for a train control system embodying this invention; and

Fig. 2 shows in a simplified and diagramm'atic way parts and circuits of the car equipment, these parts and circuits being shown more with the purpose of facilitat-' larly with the construction and manner of control of timing devices carried on the locomotive, motor car, or other vehicle; but,

in order to make clear the important requisite of such a device, and to point out to better advantage the valuable characterrs tics of this invention, it hasbeen illustrated as forming a part of a com lete train speed control system. The trac (way equipment for such a system is shown in Fig. 1, and comprises 1n general a plurality of pairs of track elements or inductors which are distrlbuted 1n the blocks of a block signaling system, or at, or near, points or zones of permanent hazard, such as yard limits, sharp curves, draw-bridges, etc;, where restricted speed limits should always be observed irrespective of tratfic conditions. While the general principle underlying this speed control system, can, of course, be applied to a large number of different forms of block signals 'stems, or to control of speed limits for xed hazards, in the sim-= plified arrangement shown in Fig. 1, the track rails 1 are divided by insulated joints 2 into track sections or blocks in the usual way .each having a track battery 3 and a track relay 4. The system may be used with, or without, the trackway fixed signals, and the signals may be of the semaphore, color-light, position light, or other suitable type; and in the simplified arrange- ;ment of Fig, 1, three-position semaphore signals X are shown conventionall without any attempt to illustrate their well 'known'structure and control circuits, it being understood that these semaphores will indicate, clear, caution, and stop; in the usual way, dependentupon presence and absence of trains in the corresponding block and the next block in advance.

Associated with each block are a number three being shown in Fig. 1. The first element or inductor of each pair, comprises a core 5 of ma netic material of a general U-shape, and iaving enlarged .pole pieces. The second track element of each pair has a coil 6, on its backyoke, and this coil 6 is included in a normally closed circuit of low resistance opened and closed respectively at the front contact 7 of a line relay 8, when said relay is deenergized and energized; The line relays 8 for the several pairs of track elements are controlled by the track relay 4 of the block next in advance, this control circuit being readily traced on the drawings. Thus, if the block next in advance is not occupied, the second track element of each pair has its coil 6' in a, closed circuit of low resistance, whereas, if said block in advance is occupied, the coils are open-ci'rcuited. 'l

The car. equipment shown in Fig. 2 has for its primary function the production of an automatic brake application in'case the vehicle travels from the first track element of a pair to the second track element of that pair, when the latter has its coil 6 on open circuit and is in the active stopping condition, in less than a certain predetermined interval of time. The several car-carried devices which cooperate through suitable circuits will first be separately referred to, after which the manner .in which they cooperate will be described. On the railway vehicle or locomotive is provided a car element L which is adapted to cooperate with the track elements located along the track by having its pole pieces 10 move directly over the pole faces of the track elements. This car element L comprises a U-shaped core 9 of magnetic material'terminating in pole pieces 10.

This core is preferablylaminated to increase its eificiency, and reduce the detrlmental effect due to eddy currents. The forward leg of the U-shaped core 9 is provided with a primary or exciting coil P, the other leg being provided with a secondary or receiving coil S. This car element L is preferably mounted on a vehicle so that the pole pieces 10 have a definite relation to the track when .the vehicle travels along the track, andis' also preferably 'houmd to protect it from snow, ice, moisture, and the like. This is preferably accomplished by housing the car element L in a suitable light non-magnetic erated by current generated in the secondary coil; and in turn is adapted to actuate a iepeater relay RR. This control relay CR and repeater relay RR have been conventionall illustrated, and in practice comprise a suita 1e winding adapted to'actuate a wellbalanced armature having contacts for cooperation with stationary contacts In practice, the control relay GR is constructed very sensitive and operates small contacts; whereas the repeater relay RR is'constructed with much heavier moving parts, and is provided with'contacts for carrying a much larger current than are the contacts of the control relay. These'relays are preferably mounted in a heavy casing supported by springs from the vehicle body. This con struction causes thejars and vibration of the vehicle to be to a certain extent absorbed and transformed by the heavy casing, thereby preventing such disturbances from reach- -1ng the relays and interfering with their operation. 7

A brake-setting or train control device K is employed which is of the normally energized type, and is constructed to apply the brakes a'short time after it has been deenergized. This brake-setting device K has been illustrated conventionally by an electropneumatic valve having a winding 64. In practice,'this brake-setting device K is constructed to pick up quickly, but drop slowly.' This slow application feature may be obtained by providing an auxiliarytiming device, such as, a' dash-pot, inertia device or the like; or it may be obtained by providing a plurality of electro-responsive devices connected in a manner so that the inherent time of the sequential operation of the devices will be cumulative when deenergized, but will not be cumulative when energized. This brakesetting device K is of a character which makes a predetermined reduction of brake pipe pressure when deenergized, and is pro vided with means for preventing the engineer from opposing an automatic brake apstructure for applying the brakes in this manner has been illustrated, since the specificform is not a part of the present invention', various forms of brake applying devices adaptable for this purpose being old in the art.

A reset switch RShas been provided which has been illustrated as a double throw push button switch 11. This reset switch is provided for the purpose of allowing the engineer to remove the restriction caused an automatic brake application, that is, release the brakes after the trainhas been ltlfi brought to a stop. This device is preferably mounted on the railway vehicle so that it is only accessible from the ground, thereby preventing the engineer from resetting the nent brake application if this push button switch 11 is fastened down.

A timecontrolled mechanism'TM is provided constructed to cooperate with the quick pick-up and slow dropaway electrical- 1y 0 erated brake-setting device K, to apply the brakes when two successive control infiuences are received in less than a predetermined time; and which will accomplish this function in a manner so that a failure of any of its essential elements will apply the brakes when a single influence is received, that is, itis constructed on the side of safety. This time controlled mechanism TM has been illustrated in a simplified manwhich is designed to" have constant speed characteristics, regardless of a slight change of voltage appliedthereto, and has been illustrated as a shunt motor, having an armature '12- and a shunt field-winding 13, which is connected across a suitablesource of E. M. F. illustrated as a battery 14,- This mot or M is connected to one member of a suitable friction clutch FO by the shaft 16. i

This clutch may take any one of various forms, suchas, an electro-magnetic clutchwhich is disengaged at certain times, or an electro-magnetie clutch of the induced current type wherein the torque transmitted depends on the induced current flowing in a conducting member, but .hasbeen illustrated for convenience as a simple form of friction clutch FC. This clutch comprises a driving member coupled to the driving shaft 16 and illustrated in the form of a cylinder; and a drivenmember or disc 17 pinned to .a Shaft 18 to be driven.

On opposite sides of the disc 17 are friction washers 19 of fiber, asbestos fabric, or other suitable material; and these washers are pressed against the end of the cylinder 15, and opposite faces. of the driven disc 17 by a spring 20 interposed between a follower plate 21 and amend member fixed to said c linder 15. The driven shaft 18 is provi ed with a worm 22 meshing with a worm wheel 23 keyed'to a shaft 2'4'suita-bly supported in bearings.

To the shaft 24 is secured-a member, conveniently termed a cam, which is shown as,

of a general circular form having a projection 26. Adjacent the cam 25 is supported on a suitable journal 27 a device which provides stops against which the projection 26 is adapted to abut, one of which is effective when this device/is in its one extreme position and the other is effective when itis' in its other extreme position. This device has been illustrated as a pallet '28 of the shape shown. This pallet 28 is held in one position against the stop 29 by a releasing or time magnet 30, and is urged to its other extreme position when this releasing magnet 30 is deenergized by a spring 31.-

Adjacent the cam 25 is mounted a circuit closer comprising a switch blade 32 normal- 1y held by gravity or a spring, ifSo desired, against the back contact 33, This switch blade 32 is provided with an insulating roller 34 adapted to be actuated by the projection 26 when the cam 25 rotates about its axis,

thereby causing the' switch blade 32 to strike,

the front contact 35. Adjacent the pallet. 28 is provided a stationary contact 36 and a movable contact 37 which are normally held in contact with each other, but are adapted to be separated when the releasing magnet 30 is deenergized, by causing the insulating plug 38 to actuate the movable contact 37. Y

Operation-Under normal conditions, that is, with the vehicle equipped with the apparatus illustrated in Fig.2 moving in a clear block along a trackway system, suchas illustrated in Fig. 1, the main control relay GR is maintained .energized through a circuit, which may be traced as follows :v beginning at the terminal B of a battery, wire 39, movable contact 40 of the control relay CR, wires 41 and 42, winding of the control relay CR, wire 43, secondary coil S of the car element L, wire 44 to a common return wire C connected to the other pole of the battery. The current flowing in this circuit is just suflicient to maintain the co n trol relay OR in its energized position, allow- 'ing of course a margin to take care of variations, such as battery .voltage, change ofv resistance due to temperature, and the like. With the control relay OR in its energized position, the movable contact 40 will be moved in the position illustrated against the tension of the spring'45, thereby completing an energizin g'eireuit for the repeater relay RR, which maybe traced as follows :beginning at the terminal B of a battery, wire 39, movable contact 40, wire 46, winding of the repeater relay RR, wire 47 back to the common return wire G.

With the repeater relay RR energized, its armature will be attracted against the tension of the spring 48, thereby completing a circuit which may be traced as follows beginning at the terminal B of a battery,

wire 49, movable contact 50 of the repeater relay RR, wire 51ywinding ofthe releasing magnet 30, wire 52 back to the common return wire C. The energizationof the releasing magnet 30 causes the pallet 28 to bear,

against the stop 29.

Assume now that the motor M is enerreleasing magnet 30 closes an exciting circuit by allowing the movable contact 37 to engage the stationary contact 36. This exciting'eircuit may be traced as follows'.

beginning at the teminal B of a battery, wire 54, push button 11, wire 55, switch blade 32,

back contact 33, wire 56, stationary contact 36, movable contact 37, wire 57, winding 64 of the brake-setting device K, wire 58, pri-' mary coil P of the car element L, wire 59 backto the common return wire C. Wit-h thisexciting circuit energized, a magnetomotive-force will be set up in the primary winding tending to send flux through the core 9 of the car element. Very little flux will, however, pass through the secondary coil S on account of the large air gap between the pole pieces 10. The. completion of this exciting circuit also energizes the normally energized brake-setting device K,-

element, thus causing a rapid increase of flux through the secondary coil S. This change of flux, it is believed, is partly due to diver-.

sion of flux. from leakage paths aroundthe primary coil P through the secondary coil S, and pa'rtly due to an increase of the total flux through the core 9, due to the decrease of reluctance of the magnetic circuit. As the car element recedes from the track ele ment, the flux again changes back to its initial value. Such rapid increase and decrease of fluxthrough the secondary coil S induces a single cycle of voltage therein similar to that of an alternating current. The secondary coil S is preferably so connected in the energizing circuit of the control relay CR that the first wave of said cycle of induced voltage is in a direction to oppose the voltage of the battery in said circuit, thereby reducing the current in said circuit sufiicient to cause the control relay OR to drop its armature. While the current change is. only momentary, the control relay CR will, however, be permanently deenergized, be-

cause its energizing circuit is interrupted by the opening of its front contact when its armature is momentarily retracted.

Assume now that the train passes over a track element provided with a coil 6. and that this coil' is included in a circuit of low.

resistance. As the car element L passes over the track element in this inactive condition, no control influence will be transmitted to the control relay .CR. This isbelieved to be due to the bucking action of the coil 6 of the track element which is now closedin a circuit of low resistance. For instance, as the car element L passes over the second track element with its coil in a circuit of low resistance, a very slight penetration of flux through the track element causes a large current .to be set up in the winding-6. This current, in accordance with well-known principles, flows in a direction to oppose the magnetism producing it, thereby preventing very little further change of flux. This slightchange of flux; through the track element also produces a slight change of flux in the. winding of the secondary coil of the car element. This slight change of flux,

however, induces insufficient voltage in the secondary coil to actuate the control relay CR.

As previously explained, the first track element of each pair in each-block, as shown in Fig. 1, is preferably constructed without any coil, so as to constitute an inert body of iron; whereas the second track elementof each pair has a-coil 6 which is in closed circuit normally, that is, when the block next in advance is not occupied, and is in open circuit under danger conditions when said block in advance is occupied. Consequently, under danger conditions, a passing car receives at each pair of track elements two successive "controls or influences, these influences being received one after the other in an interval of time which depends upon the speed of the train and the distance said track elements are apart. In practice, the.

track elements of each pair are spaced apart a distance corresponding to the speed limit it is desired to enforce at that particular point; and as indicated in the diagram shown in Fig. 1, the track elements are spaced relatively closer together near the exit end oi the block than at the entrance end. Under clear traffic conditions, since the coil 6 of the second track element'of each pair is in a closed circuit, a passing car receives only one influence at-each pair of track elements- It may be added that, if. desired, the first track element of each pair may also be provided with a coil 6, so that under clear trafiic conditions it will not communicate a stopping influence.

Considering now the operation of the car equipment, itmay be'explained at the out set that this equipment is intended to produce an automatic brake application, by acting upon the regular brake equipment of the car, in case two successive influences are communicated to the car in less than the predetermined time for which the timing mechanism is constructed or adjusted. The present invention deals. more particularly with the construction of the timing mechanism and the provisions made to assure that any failure of said mechanism to operateproperly will be automatically detected, the brakes applied, and the car controlled onthe side of safety. 4

Assume'that the car with its equipmentin the normal condition, as shown in Fig. 2,

passes over the first track element of a pair. I

This track element, as previously explained, produces a change of flux in the secondary coil S, and causes the main control relay OR to become deenergized. The deenergization of the control relay GR causes the repeater relay RR to be deenergized, and this relay RR in turn deenergizes the releasing magnet 30. This causes the pallet 28 to be moved by the spring 31, thereby actuating the movable contact 37 to open the exciting circuit through the brake-setting device K heretofore traced. Since the brake-setting device is slow acting when deenergized, it will not apply the. brakes immediately. As the pallet 28 moves away from the stop 29, the stop member 53 releases the projection 26, thus allowing the cam 25 to .be rotated by the motor M through the friction clutch FG As the projection 26 strikes the roller 34 the switch blade 32 is brought in contact with the front contact 35, thereby energizing a pick-up circuit for the control relay CR, which may be traced as fol lows :beginning at the terminal Bot a battery, wire 54, push button switch 11, wire 55, switch blade 32, front contact 35, wires 60, 61 and 42, winding of the control relay CR, wire 43, secondary coil S, wire- 44 back to the common return wire C. This causes the control relay OR to be momen-' tarily energized, thereby completing its stick circuit heretofore traced, which will keep it permanently energized.

The control relay CR again being energized causes the repeater relay RR and in turn the releasing magnet 30 to be energ zed thus again closing the exciting circuit through the brake-setting device K in time to prevent this device K from applying the brakes. Thus, the train is moving between the track elements ofthepair and the cam 25 ot' the time controlled mechanism is ro tating in the direction of the arrow.

For the first condition to be considered, assume that a predetermined speed limit is to be enforced, and that the coil 6 of the second track element of the pair is on open circuit, so that said second track element produces another operation on the control relay CR. If the train is traveling at less than the desired speed limit, the brakes are not applied; whereas if the'train is travel 'ing at a speed higher than the desired speed,

the brakes are automatically applied.

Assume first that the car is traveling at less than the desired speed limit. The car,

then,in traveling from the first track element to the second track element will take more time than that for which the timing mechanism on the car is constructed or adjusted; and consequently before the con trol relay CR drops the second time at the second trackele'ment of the pair, the cam 25 will have completed its cycle of operation, making one complete revolution back to the normal position 7 shown in Fig. 2,

and no brake application occurs, It is noted here that'the space between the second element of a pair and the first element of the next pair in the direction of traflic must be long enough such that the train, running at the proper speed, will take more time in traveling between these track elements than that for which the timing mechanism is ad justed, otherwise an automatic brake application might be improperly produced by the action of the first and last track elemerits of two succeeding pairs, in the same way as the track elements or" the same pair produce such control, as about to be explained.

Assume now that the car is traveling at a speed higher than the desired speed limit. Under these circumstances, the car will travel over the space between the two track elements of the pair in less than the time for which the timing mechanism is set; and consequently at the instant the control re--- lay CR drops the second time at the-second track element, the cam 25 has not had time to come back to its normal position, as shown. Consequently, when. the control relay CR drops, the repeater relay BB is deenergized, and the releasing magnet 30 is deenergized to allow the detent member 28 to be shifted by the spring 31, the projection 26 on the cam 25 having not passed the stop arm 62 of said detent member. As pre-' viosuly explained, when the relasing magnet 30 is deenergized and the detent member 28 released, the contacts 36-37 are opened to cut of? energizing current from the train control device K; and unless such energizing current is re-applied'in less than an interval of time, said device Kacts to apply the brakes or produce any other desired control.

Under the particular conditions assumed, the cam wheel is arrested by the stop arm 62, at the time the releasing magnet 30 is deenergized; and hence the switch arm 32 is not actuated in the manner of its normal operation, with the result that the control relayCR is not picked up, the repeater relay is not re-e'nergized, and the releasing magnet 30 is not again energized to reclose contacts 36-37, within the limited time it takes the device K to become effective. Thus, if the car reaches the second track element of the pair in question before the timing mechanism has completed its cycle of operation, there is no resetting of the control after time, the brakes are automatically applied by the device K. Furthermore, this conditionoof the devices continues or persists until the apparatus is reset by hand. It should be noted that under certain speed conditions an impulse may be received at the time the projection 26 has passed beyond the stop arm 62 but has not yet reached the stop member 53. In this case, the brakes will not be effectively applied, nor the train be effectively controlled in any other way, although the device K mayassume its deenergized condition momentarily (depending on-the slow acting characteristlc of this device K) because the projection 26 will again strike roller 34 and restore the devices CR, RR and 30, thereby re-energizlng the train control device K and finally stopping the cam 25. in its normal position. The slow acting feature of this device K .is preferably such that it will not reach its deener- 'izedcondition in the assumed case. Th s 1s, however, not absolutely necessary to make it a practical system.

Afterthe trainhas been brought to a stop in a manner .as just explained, the engineer may remove the restriction caused by the brake-setting device K by operating the push button 11 which is only accessible from the ground. By actuating the push button 11, a pick-up circuit for the control relay CR will be completed, which may be traced as follows :-beginning at the terminal of a battery, wire54, push button switch 11, wires 63, 61 and 42, winding of the control relay CR, wire 43, secondary coil S, wire 44 back to the common return wire.(). This causesthe control relay CRto be permanently energized through its stick circuit,

thereby energizing the repeater .relay RR which in turn energizes the releasing magnet 30, which rocks pallet 28 to allow the cam 25. to advance until projection 26 strikes stop member 53, ready for next operation, and also to permit the movable contact 37 to come into contact with stationary contact 36. The brake-setting device K will, however, not be energized until the push button 11 is again released by the engineer, since its energizing circnt has been interrupted at the back contact of the push button 11. This arrangement is provided so that the engineer'can not tie the push button 11 into its resetting position permanently, thereby allowing him to defeat the purpose of the speed control system.

If the coil 6 of a second track element of the pair is in a closed circuit of low resistance, a control relay CR on the. passing vehicle is not operated; and consequently, irrespective of whether the timing mechanism has completed its cycle of operation or not, no brake application occurs. Thus, under clear traflic conditions, while the timing mechanism is set into operation by the first track element of each pair, no speed limitations are enforced, and no automatic brake applications occur, except in the event of a failure of the timing mechanism to operate properly, as hereinafter explained.

he important features of this invention relate to the provision made to assure detection of failure of the timing mechanism to operate properly. Referring to Fig. 2, and bearing in mind the operation of setting the cam 25 into motion, it will be observed that unless said cam actually starts and moves the switch arm 32 against its back contact 35, then the device K, which is deenergized by the opening of the contacts 36-37, causes an automatic brake application after a time. Consequently, if the motor M is not working, due to some breakage or failure of the battery 14, or the friction clutch F C is not functioning properly, or in fact any of the driving connections of the cam 25 are broken or fail to operate, then such failure is automatically detected and is manifested'by a brake application. The releasing magnet 30, being a normally energized device, may be depended upon to perform its desired functions; and it will be evident that in case of breakage of wires, failure of the battery, or the like, detent member 28 is shifted or retracted by .the

spring 31, and opens contacts 3637 permanently, with the result that the brakes will then be automatically applied as soon as the device K has had time to operate, irrespective of the fact that the cam has been released and operated switch arm 32 to reset the control relay CR and the repeater relay It will be noted that the energizing circuit for the train control device K includes a normally closed front contact 33 of the switch arm 32'; and hence, if this switch arm should for any reason stick in the operated position (shown .in dotted lines), so as to close the pick-up circuit for the control relay CR, then the brakes will be automatically applied on account of the permanent. deenergization of the control device K. For this reason the switch arm '32, after each movement thereof, must return to its normal position shown, otherwise a brake application occurs. In short, it can be seen that all of the operating parts controlling or cont-rolled by the timing mechanism are either normally energized, so that failure results in a control on the side of safety, or else have their operation automatically checked.

It should also be observed that the reset switch RS permits restoration of the. car

the automatic speed control system just de.

scribed depends upon the presence of a certain amount of magneto-motive-force in the car element L. In order to check the presence of the necessary magneto-motive-torce, the brake-setting device K has been included in series with the primary coil P. The brake-setting-device K is so designed that if the current in the exciting circuit falls to a value to produce insuflicient magneto-motiveforce in the car element L to actuate the control relay GR under normal conditions, that the brake-setting device K will be deenergized, thus applying the brakes regardless of influences transmitted from the trackway. It should be noted that both the trackway apparatus and the car-carried apparatus have been designed and constructed so.

that a failure of'any part, which is likely to occur and commonly experienced in practice in course of time, will cause an automatic brake application upon such failure.

Another characteristic feature of the particular type of speed control system disclosed is that, immediately upon a change in traflic conditions ahead, the speed restrictions enforced by the pairs of track elements are automatically removed. For example, suppose that a train is in the blockI approaching the second pair of track .elements shown, and is reducing speed to avoid a brake application, because there is another train ahead in the block J. If, now, the train ahead leaves the block J, the signal X at the entrance to that block changes to the caution position, signifying to the engineer that he may resume speed; and at the same time the line relays 8 are energized to close the circuit for the coil 6 of the second track element of each pair, so that the train may travel at any speed by said pairs of track elements without receiving automatic control. Such automatic release of the speed limits imposed in a caution block as soon as traffic conditions in the next block in advance clear up is important from a standpoint of facilitating train movement, since it allows a train to accelerate as soon as conditions ahead change and permit such acceleration. Also, in case there is a change in trafiic conditions in the next block in advance after a train has entered a block, the second track element of each pair will be put in the active stopping condition, with the result that the brakes are app1ied,'if the train in said block is exceeding the safe speed at these respective pairs of track ele-' ments.

These features of automatic release, or automatic enforcement of train control, in the event of a change in trafiic conditions in advance, are characteristic of the type of system to which the present invention re-.

lates, but aside from their combinational relation to the features of the present invention, no claim thereto is made herein.

Although only one specific embodiment of the present invention has been illustrated, both with regard to the trackway apparatus and the car-carried apparatus, it should be understood that various modifications may be used to adapt the invention to the various conditions encountered in practice without departing from the spirit and scope of the present inventionr For instance, the trackway devices may be controlled in any suitable. manner, dependent upon the block signal system in connection with which they are used, for instance, an entirely automatic system, or an auto-manual system with the employment of various sources of current; or pairs of permanently active track elements each comprising a core-similar to the core 5 may be employed where permanent hazards, such as, short curves, approaches to bridges, yard limits,.and the like, are existing along the trackway. Further, the carcarried apparatus may be modified to apply it to the various t'rackway systems commonly employed. For instance, the necessary modifications may be made so that the same apparatus can be used when either end of the vehicle is running ahead, either. for double. track or single track systems, so that no' control influence will be received when running against traffic in either case, as is obvious to those skilled in the art.

Having now fully shown and described my invention, what I desire to secure by Letters Patent, is

1. In a train control system, the combination with a pair of spaced track devices, automatic brake-setting apparatus on a vehicle acting upon the regular brake equipment thereof and having its operation dependent upon the speed of the vehicle in passing between said track devices, said apparatus being influenced by said track devices and comprising, a brake-setting device, a normally energized stick relay which if deenergized tends to actuate said brakesetting apparatus, a normally inactive time controlled mechanism automatically set into operation by said relay when said relay is influenced by a track device for removing the tendency to actuate said brake-setting device, whereby failure of saidmechanism to become active in response to the actuation of the relay by a track device causes an automatic application of the brakes.

2. Brake control mechanism acting upon the usual braking equipment on a railway vehicle comprising, a brake-setting device, control means including a time controlled device maintained inactive by a normally energized winding adapted to be influenced from the trackway for actuating said brakesetting device if twosuccessive control in fluences are received n less than a predetermined time, and also including means for actuating said brake-setting device if said time controlled means fails to start to operate due to deenergization of said winding. 4 j

3. Brake control mechanism acting upon the usual braking equi ment on a railway vehiclecomprising, a rake-setting device, a time controlled means, control means adapted'to be influenced from the track way for starting said, time controlled means through a period of o eration and for actuating said brake-setting device, said time controlled means restoring said brake-setting device if a single control influence only is received before said time controlled device has completed its period of operation, whereby control means actuates said brakesetting device ifsaid controlled means fails to operate.

t. Brake control mechanism acting upon the regular braking equipment of a railway vehicle comprising, a normally energized slow releasing brake-setting device, a time controlled device, control means governed from the trackway for starting said time controlled means and for deenergizing said brake-setting device at the sametime, and means efiective only after said time conineffective to restore said control means if said control means is operated twice in succession within less than a predetermined interval of time. I

6. Automatic train control apparatus comprising, a slow acting brake-setting device acting upon the usual brakin equipment on a railway vehicle,"means including a rotat able member controlled by influences from the trackway for actuating said brake-setting device if two successive control influences are received in less than a predetermined time, said means including means for actuating said brake-setting device if said member fails to star-t into operation in response to an influence. v

7. Brake control mechanism acting upon the regular air brake equipment of a railw way vehicle comprising, a normally energized and normally inactive slow acting brake setting appliance of the type which it deenergized remains deenergized until restored, control means actuated by influences received from the trackway for deenergizing' said brake-setting appliance, means set into operation by said control means upon the reception of a control influnce effective to restore said control means and in turn restore said wslow acting brake-setting appliance to normal before said appliance has assumed its active condition, said last mentioned means being ineffective to restore said control means to normal if said control means is operated twice in succession Within less than a predetermined interval of time,

8. Automatic train control apparatus comprising, a slow acting brake-setting device acting upon the usual braking equipment on a railway vehicle, means controlled by influences from the trackway for initiating the actuation of said brake-setting device, a movable member urged to move at a definite speed, and means actuated by said member for preventing said-brake-setting device be coming active if the successive control influences are separated more than a predetermined interval of time.

9. An automatic train control system comprising, a brake-setting device acting upon the usual automatic braking equipment of a railway vehicle, means controlled by influences received from the trackway for actuating said brake-setting device if two successive influences are receivedin less than a f predetermined time and including a time element device normally held against movement and performing a cycle of operation if. initiated, said means being constructed to cause said brake-setting device to be actuated if said time element device is released but does not start to 0 rate.

10. Train contro apparatus for railway vehicle's comprising, a brake-setting appliance, a normally inactive time controlled device having a normal condition, control means for initiating a change of said device from its initial position and at the same time initiating operation of said appliance, and

means effective only after the time controlled device has actually changed from its normal condition for restoring a said appliance, whereby the operation of the time controlled device is automatically checked and failure thereof produces a brake application.

11. In a train control system of the type described, a movable member, releasable means normally maintaining said member stationary, means tending to move said memher at a predetermined rate of speed, and automatic means manifesting failure of said member to move when released.

12. In a train control system adapted to determine the application of the brakes on railway vehicles dependent upon the time taken by such vehicles to traverse the space between two successive control points comprising, a rotary member, means for moving said member from an initial position back to that position in a certain interval of time, releasable means adapted to be influenced from the trackway for holding said member in its initial position, and automatic means for applying the brakes of the vehicle whenever said member is released and fails to rotate.-

13. In a train control system adapted to determine the application of the brakes on railway vehicles dependent upon the time taken by such vehicles to traverse the space between two successive control points comprising, a normally energized brake-setting appliance, a time element device, automatic control means adapted to be influenced from the trackway for simultaneously settin the time element device into operation an deenergizing the brake setting appliance, and automatic means effective only after the time element device commences its operation for re-energizing said appliance.

14. In a system of train control of the general character described, a time element device having a normal condition and when set into operation automatically returning to that condition after a lapse of a predetermined time, means conditioning said device for operation, and means preventing it returning to its normal condition if again conditioned in less than a predetermined time. v I

15. Train control apparatus for railway vehicles comprising, a normally energized brake-setting appliance adapted when deenergized to cause an automatic application of the brakes, an energizing circuit for said appliance, an element movable from an initial position back to that position in a predetermined time, control .means responsive to influences from the trackway for simultaneously initiating the movement of said element and for breaking said energizing circuit at one point, and a circuit controller shifted temporarily by the movement of said element near its initial position, said circuit controller while shifted opening said energizing circuit at another point and also acting to restore the control means to normal.

l6. Car-carried apparatus for automatic train control systems of the type in which the brakes are automatically applied after two successive control influences are received inless than a predetermined interval of time comprising, a normally energized brake control device, a time element device, a normally energized electro-responsive device having a contact closed when said electro-responsive device is energized which contact is included in the energizing circuit of said brake control device for directly maintainin said brake control device inactive and having means associated therewith for maintaining said time element device in its normal condition, said time element device including means for re-energizing said electro-responsive device only once during the time of each operation of said time element device, and means accessible only from the ground for restoring said electro-responsive device to normal.

17 Speed responsive brake control apparatus on a railway vehicle of the general type described comprising, a movable element, a constant speed motor tending to drive said element, releasable means maintaining said element in an initial position, and automatic brake applying means having its operation initiated when said releasable means is ac tuated to release said element and causing an automatic brake application if said ele-' ment fails to move.

18. Apparatus for governing the regular braking. equipment of railway vehicles dependent upon the speed thereof at predetermined points along the track comprising, a normally energized control means of the type which if momentarily deenergized remains deenergized until restored and located on the vehicle and actuated by inductive control influences transmitted from the trackway, a normallyenergized and normally inactive slow acting brake setting appliance adapted to have its energizing circuit broken by operation of said control means, a time element device, and normally open contacts controlled by said device for restoring said control means to normal, said normally open contacts when closed by said time element device restoring said control means and in turn re-energizing said slow acting brake setting appliance before said appliance has assumed its active condition and said open contacts if closed breaking the energizing circuit for said brake setting appliance, whereby accidental displacement of said contacts into the restoring position cannot efl'ect permanent energization of said appliance.

19. An automatic train control system for vrailways comprising, car-carried apparatus for controlling the speed of the train including a rotatable device set into operation in response to control influences transmitted inductively from the trackway, a normally energized brake-setting appliance which if deenergized applies the brakes of the train, a normally energized electro-responsive device for maintaining said rotatable device and said brake-setting appliance inactive, a stick relay for controlling said appliance, and movable means for pickin up said stick relay by rotation of said rotatable device upon deenergization of said electro-responsive device,

whereby failure of said rotatable device to rotate upon deenergization of said electroresponsive device causes the brakes to be automatically applied.

20. Automatic brake control apparatus for railway vehicles of the general type described comprising, means for receiving control influences from the trackway, a time controlled mechanism having -a normally open circuit controller closed once for each" influence received by said mechanism providing the lapse of time between successive influences is more than a predetermined interval of time, and automatic means manitesting closure of said circuit controller for more than a certain time interval.

21. Brake control equipment for railway vehicles dependent upon the speed thereof at predetermined control points along the track comprising, a rotary member, means to drive said member at a constant rate, control means for holding or releasing said member and adapted to be influenced from the trackway for arresting movement of said member at a predetermined point, and automatic means for applying the brakes if said member fails to move when released by the control means.

22. Brake control equipment for railway vehicles dependent upon the speed thereof at predetermined control points along the track comprising, a time element device changeable from a normal position and automatically returning to that position after a lapse of a predetermined time, and control means adapted to be influenced from the trackway for ermanently arresting the change of said evice whenever two successive operations of said control means occur Within less than said predetermined time.

23. Brake control equipment for railway vehicles dependent upon the speed thereof eiiective only after the time element device has partially changed for picking up the stick relay and.thereby restoring the brakesetting appliance. ,7

An automatic train control system for raiiways comprising, car-carried apparatus for controlling the speed of the train including a rotatable device set into operation in response to control influences transmitted inductively from the trackway, a normally energized brake setting appliance which if deenergized applies the brakes of the train, a normally energized electro-responsive device foizmaintaining said rotatable device and said brake setting appliance inactive, a stick relay for controlling said appliance, and movable means for picking up said stick relay by rotation of said rotatable device upon deenergization of said electro-respon I sive device, said movable means while in its pick-up position cutting energy off of said brake setting appliance, whereby accidental displacement of said movable means into the pick-up position effects an automatic brake application.

25. An automatic train control system comprising, a rotatable time element device normally tending to rotate but maintained in its normal condition by a normally energized stick electro-responsive device and adapted to perform a predetermined cycle of operation if deenergized during which cycle it is capable of only once picking up said stick electro-responsive device, and normally energized brake control means governed by said eleetro-responsive device.

26. An automatic train control system comprising, a car-carried relay normally energized by a circuit including a front contact of p v which coil if deenergized allows said time element device to perform a predetermined cycle of operation, and means governed by said time element device for closing a pickup circuit for said relay.

27. An automatic train control system comprising a normally energized stick relay, inductive influence communicating means partly on the vehicle and partly along the trackway for transmitting control influences to actuate said relay, a rotatable time element device normally tending to operate but maintained in its normal condition by a normally energized electro-rcsponsive device and adapted to perform a predetermined cycle of operation if said electro=responsive device is deenergized said time clement device closing a pick-up circuit for said stick relay in said cycle of op- 'eration, and normally energizedbrake control means governed by said time element device.

28. An automatic train control system comprising, a control relay normally energized by a circuit including-a front contact of said relay, a normally energized brake control device; and a time element device including means rotatable about an axis tendingto move from its normal position, said time element device including a normally energized coil controlled by said control relay maintaining said rotatable means in its nor mal position and allowing it to complete a cycle of operation if momentaril deenergized, and including means for picking up said control relay.

29.. Automatic train control apparatus comprising, a slow acting brake-setting device acting u on the usual braking equipment on a rai way vehicle, means controlled by influences transmitted from the trackway for initiating the actuation of said brake-setting device, a movable member urged to move through a certain c cle of operation, and means actuated by sai mem her for preventing said brake-setting device becoming active if the successive control influences are separated by more than a. predetermined interval of time.

30. An automatic train control system comprising a pivotally supported member normally held against rotary movement, means tending to assumea condition to ermit actuation of said member throng a certain cycle of operation, means tending to move said member, automatic means manifestingfailure of said member to movmwhen released, and inductive influence communicating means located partly on the vehicle and partly along the trackway for governing said first mentioned means.

31. An automatic train control system comprising, a slow acting brake-setting device acting upon the usual braking equipment of a railway vehicle, means controlled by influences transmitted from the trackway for initiating the actuation of said brake-setting device, a movable member controlled by said means urged "to perform a certain cycle of operation in acertain period of time, and means actuated bysaid member for preventin said brake-setting device from applying t e brakes if the successive influences transmitted are separated by a predetermined space of time. 7

32. An automatic train control'system for railways comprising, car-carried apparatus for controlling the speed of the train including a rotatable device set into/operation in re,- sponse to control influences transmitted from the trackway, a normally energized slow acting electro-pneumatic valve which if deenergized applies the brakes of the train after an interval of time, a stick relay for controlling said valve, and movable means for picking up said stick relay by rotation of said rotatable device upon deenergization of said electro-responsive device, wherebyvv failure of said rotatable device to rotate upon vice causes the brakes to be automaticall applied after said'interval of time.

33. An automatic train control system comprising, a normall energized brake-setting device acting on t e usual air brake system which device applies the brakes when deenergized, normally energized apparatus controlling said brake-setting device and rendered eflfective until reset it momentarily deenergized, a timeelement device for resetting said apparatus effective to reset said deenergization of said electro-responsive dea normally energized electro-responsive de- 1 vice for maintalnin said rotatable device and said brake setting appliance inactive,

a stick relay for controlling said appliance,

movable means for picking up said stick relay by rotation of said rotatable device upon deenergization of said electro-responsive device, whereby failure of said rotatable device to rotate upon deenergization of said electro-responsive device causes the brakes to be automatically applied, and means accessible only from the ground for restoring said apparatus to normal, said last mentioned.

means functioning only to restore said ap paratus if it is moved to its restoring position and is then returned and left in its normal position.

35. 'lrackway equipment for enforcing speed restrictions through a block by suita le car-carried train control apparatus comprising, a trackway including the usual track rails, and a plurality of pairs of track elements spaced relatively close together at different distances apart and located outside of the track rails at intervals in the'block, one element only of each pair having a coil thereon closed in a deenergized circuit of low resistance when there are no trains in the block next in advance. i

Intestimony whereof I hereto afiix my signature.

- CHARLES S. BUSHNELL. 

